Conventionally, as an interlayer insulation film or the like used in semiconductor devices of electronics instruments, polyimide resins or polybenzoxazole resins have been widely used because of their excellent heat resistance and mechanical properties. In order to improve productivity or to obtain higher precision in film formation through providing resins with photosensitivity, various attempts have been made on photosensitive polyimide or photosensitive polybenzoxazole resins. For example, there has been commercialized a negative photosensitive resin in which a photo-crosslinkable group is incorporated into a polyimide precursor through ester boding or ionic bonding. Further, as a positive photosensitive resin, a composition that comprises a polyimide precursor and a quinonediazide compound is described in Japanese Patent Laid-open Publication Nos. 5996/1993 and 98601/2000 and the like. There is also described a composition that comprises a polybenzoxazole precursor and a quinonediazide compound in Japanese Patent Laid-open Publication No. 237736/1999. However, these systems still require improving resolution, electrical insulation, thermal shock resistance, adhesion, and other properties. These systems have problems such as thickness reduction (volume shrinkage) after curing, multi-stage baking on curing and atmosphere control on curing, so that it is pointed out that these systems cannot be easily handled in practical industrial application. In addition, there still have a problem that pattern shape changes before and after post-baking.
Various kinds of positive photosensitive resin compositions capable of improving various properties of cured products have been proposed. For example, Japanese Patent Laid-open Publication No. 206058/2004 (Patent document 1) discloses a positive photosensitive composition comprising an epoxy compound having two or more epoxy groups per one molecule, a compound generating a curing catalyst and a sulfonate ester, which is used as an underfill. It is described that a monomer which is in a liquid state at room temperature is suitable for the epoxy compound. Further, Japanese Patent Laid-open Publication No. 191816/2004 (Patent document 2) discloses a positive photosensitive composition which comprises a novolak resin, a quinonediazide compound, an epoxy compound having two or more epoxy groups per one molecule, and a compound generating acid or base. The composition is less hygroscopic and has higher reliability. It is described that there may cause problems in film properties after curing or pattern-forming performance such as solubility of exposed portions on development, when the blending ratio of the epoxy compound is too large or too small. Still further, in Japanese Unexamined Patent Publication No. 2004-258070 (Patent document 3) discloses a positive photo-resist composition which comprises a novolak resin, a quinonediazide compound, a specific compound that reacts with the novolak resin by action of an acid, and a compound that thermally generates an acid. This photo-resist composition provides an insulating film having reduced deformation of patterns when patterns are formed by heat curing. It is described that there may cause problems in film properties after curing or pattern-forming performance such as solubility of exposed portions on development, when the blending ratio of the specific compound is too large or too small.
However, in these documents, it is not described that the change in pattern shape before and after post-baking is affected by the kinds of epoxy resins used.
Patent document 1: Japanese Patent Laid-open Publication No. 206058/2004
Patent document 2: Japanese Patent Laid-open Publication No. 191816/2004
Patent document 3: Japanese Patent Laid-open Publication No. 258070/2004